MultipartResolver

All Known Implementing Classes:

CommonsMultipartResolver, StandardServletMultipartResolver
```
public interface MultipartResolver
```
A strategy interface for multipart file upload resolution in accordance with RFC 1867. Implementations are typically usable both within an application context and standalone.
There are two concrete implementations included in Spring, as of Spring 3.1:
- CommonsMultipartResolver for Jakarta Commons FileUpload
- StandardServletMultipartResolver for Servlet 3.0 Part API
There is no default resolver implementation used for Spring DispatcherServlets, as an application might choose to parse its multipart requests itself. To define an implementation, create a bean with the id "multipartResolver" in a DispatcherServlet's application context. Such a resolver gets applied to all requests handled by that DispatcherServlet.
If a DispatcherServlet detects a multipart request, it will resolve it via the configured MultipartResolver and pass on a wrapped javax.servlet.http.HttpServletRequest. Controllers can then cast their given request to the MultipartHttpServletRequest interface, which permits access to any MultipartFiles. Note that this cast is only supported in case of an actual multipart request.
```
 public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) {
   MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
   MultipartFile multipartFile = multipartRequest.getFile("image");
   ...
 }
```
Instead of direct access, command or form controllers can register a ByteArrayMultipartFileEditor or StringMultipartFileEditor with their data binder, to automatically apply multipart content to command bean properties.
As an alternative to using a MultipartResolver with a DispatcherServlet, a MultipartFilter can be registered in web.xml. It will delegate to a corresponding MultipartResolver bean in the root application context. This is mainly intended for applications that do not use Spring's own web MVC framework.
Note: There is hardly ever a need to access the MultipartResolver itself from application code. It will simply do its work behind the scenes, making MultipartHttpServletRequests available to controllers.
Since:

29.09.2003

Author:

Juergen Hoeller, Trevor D. Cook

See Also:
MultipartHttpServletRequest, MultipartFile, CommonsMultipartResolver, ByteArrayMultipartFileEditor, StringMultipartFileEditor, DispatcherServlet

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`cleanupMultipart(MultipartHttpServletRequest request)` Cleanup any resources used for the multipart handling, like a storage for the uploaded files.
`boolean`	`isMultipart(HttpServletRequest request)` Determine if the given request contains multipart content.
`MultipartHttpServletRequest`	`resolveMultipart(HttpServletRequest request)` Parse the given HTTP request into multipart files and parameters, and wrap the request inside a `MultipartHttpServletRequest` object that provides access to file descriptors and makes contained parameters accessible via the standard ServletRequest methods.

- Method Detail
  - isMultipart
```
boolean isMultipart(HttpServletRequest request)
```
    Determine if the given request contains multipart content.
    Will typically check for content type "multipart/form-data", but the actually accepted requests might depend on the capabilities of the resolver implementation.
    
    Parameters:
    request - the servlet request to be evaluated
    
    Returns:
    whether the request contains multipart content
  - resolveMultipart
```
MultipartHttpServletRequest resolveMultipart(HttpServletRequest request)
                                             throws MultipartException
```
    Parse the given HTTP request into multipart files and parameters, and wrap the request inside a MultipartHttpServletRequest object that provides access to file descriptors and makes contained parameters accessible via the standard ServletRequest methods.
    
    Parameters:
    request - the servlet request to wrap (must be of a multipart content type)
    
    Returns:
    the wrapped servlet request
    
    Throws:
    
    MultipartException - if the servlet request is not multipart, or if implementation-specific problems are encountered (such as exceeding file size limits)
    See Also:
    MultipartRequest.getFile(java.lang.String), MultipartRequest.getFileNames(), MultipartRequest.getFileMap(), javax.servlet.http.HttpServletRequest#getParameter, javax.servlet.http.HttpServletRequest#getParameterNames, javax.servlet.http.HttpServletRequest#getParameterMap
  - cleanupMultipart
```
void cleanupMultipart(MultipartHttpServletRequest request)
```
    Cleanup any resources used for the multipart handling, like a storage for the uploaded files.
    
    Parameters:
    request - the request to cleanup resources for

Interface MultipartResolver

Method Summary

Method Detail

isMultipart

resolveMultipart

cleanupMultipart